//本函数必须传递三个参数，第一个参数为添加轮播的容器，第二个参数为按钮的大小，第三个参数是按钮形状，1为圆形，其余值为方形
//轮播图容器结构为li下嵌套img，li的position值也必须为absolute
function lunbo(element,size,css,t){
				var index = 0;
				var len = element.find("li").length;
				function next(){					
						element.find("li").eq(index).animate({"z-index":-2}).siblings().not(div).animate({"z-index":-3});
						index++;
						if(index == len){
							index = 0;
						}
						$(div).find("div").eq(index).css("background-color","#ccc").siblings().css("background-color","#FF3C3C");
				}
				function forward(){					
						element.find("li").eq(index).animate({"z-index":-2}).siblings().not(div).animate({"z-index":-3});
						index--;
						if(index == -1){
							index = len;
						}
						$(div).find("div").eq(index).css("background-color","#ccc").siblings().css("background-color","#FF3C3C");
				}
				var div	= document.createElement("div");
				$(element).css("position","relative");				
				for (var i = 0;i<len;i++) {
					div.appendChild(document.createElement("div"));					
				}
				$(div).find("div").css("width",size + "px").css("height",size + "px").css("background-color","#FF3C3C")
				    			  .css("display","inline-block").css("margin-left","10px");
				if (css == 1) {
					$(div).find("div").css("border-radius","50%");
				}
				var width = (($(div).find("div").width())/2)*len + "px";
				$(div).css("position","absolute").css("top",$(element).find("li").height() - 30).css("left","calc(50% - "+width+")")
				 	  .css("z-index","5");
				$(div).find("div").mouseover(function(){
					index = $(this).index();
					$(this).css("background-color","#ccc").siblings().css("background-color","#FF3C3C");
					$(element).find("li").eq(index).css("z-index","-1").siblings().not(div).css("z-index","-3");
				})
				$(div).appendTo(element);
				$(element).mouseenter(function(){
					clearInterval(timer);
				})
				$(element).mouseleave(function(){
					autoplay();
				})
				function autoplay(){
					timer = setInterval(next,t);
				}
				autoplay();
			}